import java.util.*;
class Example2_5 
{
	public static void main(String args[]) 
	{
		int start = 0,end,middle;
		int a[] = {12,45,67,89,123,-45,67};
		int N = a.length;
		for(int i = 0;i<N;i++)
		{
			for(int j=i+1;j<N;j++)
			{
				if(a[j]<a[i])
				{
					int t = a[j];
					a[j] = a[i];
					a[i] = t;
				}
			}
		}
		Scanner scanner = new Scanner(System.in);
		System.out.println("输入整数，程序判断该整数是否在数组中：");
		int number = scanner.nextInt();
		int count = 0;
		end = N;
		middle=(start+end)/2;
		while(number!=a[middle])
		{
			if(number>a[middle])
				start = middle;
			else if(number<a[middle])
					end = middle;
					middle = (start+end)/2;
					count++;
					if(count>N/2)
					break;
		}
		if(count>N/2)
		System.out.printf("%d不在数组中.\n",number);
		else
		System.out.printf("%d在数组中.\n",number);
	}
}
